Gitzo is owned by Manfrotto, or rather Gitzo is another brand name in the Manfrotto family so most retailers that sell one sell the other.
For me it is always a cost/function equation, where I need to I will get the most expensive (hence two 1DX MkII’s), when there is little to no functional difference between things I normally struggle to justify spending extra, that isn’t the equation most people here work to. I have a minimum of three tripods as there isn’t one made that can do all the things I want well enough, so if I spend $1,000-2,000 per set on legs I am looking at close to $5,000 just on legs, as it is I have less than $1,000 invested in leg sets, a Giotto mini tripod, the Manfrotto 055 carbon for general use and travel, and the Manfrotto 058b for studio and serious outside outings, this leaves me $4,000 to spend on lenses! If I only had one leg set and used it every day i’d get the RRS or Gitzo because the small differences in functionality would make the extra investment worthwhile.
Tripod heads on the other hand are completely different, I have found the differences between lower priced models and the higher end to have functional differences that, to me, render the lower cost alternatives unusable. Things like sag after setting, gear backlash, plate/clamp incompatibility, practical load limits etc have meant I just don’t see savings on heads worthwhile. But I would say get the right head for whatever it is that you intend to do and take a look at some of the newer variations that do add functional improvements to the all to common ball in a cup. Things like the Arca-Swiss p0 series, the Uniqueball (which seems to have been adopted/renamed as Flexshooter) and the Acratech GP (my main general head since they came out) all deserve a well informed look at, support your local store by all means but know there is a much better and feature rich choice of high quality alternative heads that might suit your case use better.
Similar thing with plates, few things are more frustrating than being at the top of a mountain for a dawn long exposure shot to then strip the thread of your camera baseplate because the damn body plate doesn’t have a good contoured fit so it sags during the exposure and you tightened it too much! ‘Universal’ means it doesn’t work well enough with anything!